[RFC PATCH 1/1] dmaengine: apple-admac: suppress bind/unbind sysfs attributes

[Fan Wu]

apple-admac stores its dma_device and channels in devm-managed memory and
does not implement dma_device.device_release. At registration, the
DMAengine core emits a diagnostic that the driver is not safe to unbind
while in use, and on channel unregister it emits WARN_ONCE if a channel
still has clients. admac_data is released by devres after admac_remove()
returns, so if a client still holds a channel at that point it may
reference the freed dma_chan and admac_data.

As the controller is a fixed SoC resource, remove the standard
driver-core sysfs bind/unbind controls. It also opts the driver out of
CONFIG_DEBUG_TEST_DRIVER_REMOVE.

This RFC does not define behavior for other removal paths, such as
device or DT-overlay removal. Guidance is requested on whether this
restriction is appropriate, or whether the driver should retain manual
bind/unbind support.

This issue was found by an in-house static analysis tool.

Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@xxxxxxxxxx>
---
 drivers/dma/apple-admac.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/apple-admac.c b/drivers/dma/apple-admac.c
index 04bbd774b3b4..b448ee323454 100644
--- a/drivers/dma/apple-admac.c
+++ b/drivers/dma/apple-admac.c
@@ -946,6 +946,7 @@ static struct platform_driver apple_admac_driver = {
 	.driver = {
 		.name = "apple-admac",
 		.of_match_table = admac_of_match,
+		.suppress_bind_attrs = true,
 	},
 	.probe = admac_probe,
 	.remove = admac_remove,
--
2.34.1